玉米Proline responding 1(pro1)突变在蛋白合成和细胞...（四）
Figure 7 Evidence of Aberrant Cell Cycle in pro1-ref.
(A) Cell cycle analysis of 14 DAG seedlings of wild type, pro1-ref and pro1-ref cultivated on medium supplemented with 3 mM L-proline. wt, wild type; pro1, pro1-ref.
(B) Cell cycle analysis of 18 DAP endosperms of wild type and pro1-ref. wt, wild type; pro1, pro1-ref.
(C) Cell cycle analysis of 24 DAP endosperms of wild type and pro1-ref. wt, wild type; pro1, pro1-ref.
The small graphs (I, II, and III) inserted in A, B, and C respectively are the cell cycle diagrams of 14 DAG seedlings, 18 and 24 DAP endosperms analyzed by flow cytometry. The 2C and 4C are DNA contents of the nuclei at stage G1 and S phase of 14 DAG seedlings respectively. The 3C and 6C are DNA contents of the nuclei at stage G1 and S phase of 18 and 24 DAP endosperms. The 12C and >= 24C are DNA contents of endoreduplicated nuclei at stage S phase of 18 and 24 DAP endosperms. For each sample, three independent biological replicates were performed. Bars represent average values ± SD, n=3 replicates (No refers to P > 0.05, * refers to P < 0.05, ** refers to P < 0.01, Student’s test).
用流式细胞仪进行细胞周期分析表明，与野生型相比，pro1-ref幼苗的细胞周期受到抑制，表现为4C DNA减少，相应的2C DNA增多，可能DNA扩增受到抑制(Figure 7A)。将pro1-ref突变体与野生型幼苗在萌发后移至含3mM的L-脯氨酸中培养9-10天，收取整苗进行细胞周期分析，结果表明，在3mM的L-脯氨酸中培养的pro1-ref突变体幼苗细胞周期基本恢复至野生型水平(Figure 7A)。籽粒胚乳细胞的细胞周期分析进一步证实了G1到S期转换的抑制(Figure 7B和C)。这些结果表明，pro1-ref突变体中L-脯氨酸的缺乏抑制了细胞周期，外源添加L-脯氨酸可以促进pro1-ref突变体的细胞周期恢复正常。
Pro1基因功能的解析，有助于了解脯氨酸在植物生长与发育中的调控作用机理，进而更全面地理解它在细胞生命活动过程中的重要作用，使人们对脯氨酸的功能有了新的认识。
